1. Field of the Invention
The present invention relates to an apparatus for cleaning the surface of a sheet. More particularly, the invention is concerned with an apparatus for removing dust or contaminant attached to the surface of a sheet such as a sheet of a metal, e g., iron, copper or aluminum, on which a paint, ink or the like is to be applied, or a sheet of paper, film and so forth which is to be used for a printing purpose.
2. Description of the Prior Art
When a paint or an ink is to be applied to a metallic sheet, plywood sheet or the like, if any dust or other contaminant remains on the sheet surface, such dust or contaminant will be strongly bonded to the sheet surface by the paint or ink unless it is suitably removed. Therefore, painting apparatus or printing apparatus usually employs a dust removing device such as a brush-roller type device or a vacuum-type device capable of removing the dust or contaminant immediately before the painting or printing.
These known dust removing devices such as the brush-roll type or vacuum-type cannot satisfactorily remove fine dust particles instantaneously. Fine dust particles remaining on the sheet surface undesirably form pin-holes or color spots so as to seriously impair the quality of the sheet product.
In order to obviate these problems, the present inventor has proposed, in Japanese Patent Unexamined Publication No. 63-12388, a cleaning apparatus having a roll with tackiness so that the sheet surface is cleaned as the roll is made to roll on the sheet surface.
This cleaning apparatus, however, requires that the painting or printing apparatus has to be temporarily stopped when the cleaning is to be conducted. In addition, the cleaning operation with the roll has to be executed manually.
Thus, there is a demand for apparatus which can automatically clean the sheet surface.